Rotary hook for sewing machines



March 31,1936. H. LE VESCONTEH 2,035,959

ROTARY HOOK FOR SEWING MACHINES Filed Nov. 50, 1934 I 2 Sheets-Sheet l r :30 J 10 w -5 March 31, 1936. I H J LE VEscON TE 21335369 ROTARY HOOK FOR SEWING MACHINES Filed Nov. 30, 1934 2 Sheets-Sheet? Patented Mar. 31, 1936 UNITED STATES PATENT OFFICE ROTARY HOOK FOR SEWING MACHINES Application November 30, 1934, Serial No. 755,494

7 Claims.

The present invention relates to new and useful improvements in a rotary hook for a lock stitch sewing machine and more particularly to improved means for furnishing lubricant to the interengaging parts between the rotary hook and the stationary bobbin casing.

An object of the invention is to provide a rotary hook wherein means are provided for directing lubricant from a source of supply adjacent the axis thereof to the connecting portions between adjacent spokes and thence to the interengaging parts between the rotary hook and the stationary bobbin casing.

A further object of the invention is to provide a rotary hook wherein means are provided for directinglubricant from a source of supply at the axis thereof to the connecting portions between adjacent spokes and wherein means are provided for forming channels along said connecting portions to the inner face of the hook rim whereby lubricant is caused to fiow by centrifugal force to the interengaging parts between the rotary hook and the stationary bobbin casing;

The above and other objects of the invention will in part be obvious and will be hereinafter more fully pointed out.

In the accompanying drawings:

Figure 1 is a side elevation, in section, showing the assembled rotary hook, the actuating shaft therefor, and the bushing in which theshaft rotates.

Figure 2 is a front elevation of the hook'with the bobbin casing removed.

Figure 3 is a rear elevation of a portion of the hook.

Figure 4-is a perspective view showing one of the channel forming members.

Figure 5 is a sectional view taken along the line 5-5 of Fig. 2.

Figure 6 is a side elevation, in section, similar to Fig. 1, but showing amodified form of the invention.

Figure 7 is a front elevation of the hook, shown in Fig. 6, with the bobbin casing-removed.

Figure 8 is a sectional view taken along the line 8-8 of Fig. '7.

The invention relates generally to means for furnishing lubricant to the interengaging parts between the rotary hook and the stationary bobbin casing. The rotary hook is provided with a rim portion, a hub and spokes connecting the hub and rim portions. The hub of the rotary hook is fixed to the end of a rotating shaft in position to leave a recess at the end thereof and the bobbin casing is mounted within and supported by the hook. The bobbin casing is provided with a circumferential rib which fits within and moves in a groove or raceway in the hook rim and thus prevents relative lateral movement between the hook and the casing. A portion of the bobbin casing engages a fixed part of the sewing machine in order to prevent rotation thereof within the hook. The actuating shaft for the hook is supported in a bushing which is mounted in a hearing bracket depending from the work support of the sewing machine. The bushing is provided with an opening through which oil may flow from a source of supply to a central bore in the actuating shaft. The bore communicates with the recess in the hub. The hub is provided with radial ports leading from the recess therein to the web portions connecting adjacent spokes. The web portions may be provided, in one instance, with grooves leading to the inclined edge of the rim portion or with removable channel members which form oil channels leading to the inclined edge of the rim. Oil admitted to the recess in the hub through the shaft will be caused by centrifugal force to flow through the ports to the web or connecting portions between adjacent spokes from which point the oil will follow the inclined inner face of the hook rim to the interengaging parts between the rotary hook and the stationary bobbin casing.

Referring more in detail to the accompanying drawings, and particularly at this time to Figs. 1-5 inclusive, the invention is shown as applied to a sewing machine having a work support Ill which is provided with a depending bearing bracket I l within which is mounted a bushing I2. The actuating shaft I3 is mounted within the bushing l2 and the rotary hook I4 is secured to the end of the shaft by a screw l5 or the like, passing through the hub IS. The particular manner in which the actuating shaft for the rotary hook is driven forms no part of the present invention and it is to be clearly understood that it may be driven in any suitable manner. For purposes of illustration, however, the actuating shaft l3 may be driven by suitable intermeshing gears, as shown in the copending application of George Sauer, Serial No. 688,512, filed September '7, 1933, and described in detail in the copending application of Norman V. Christensen et a1., Serial No. 670,186, filed May 9, 1933. The shaft 13 may also be driven in the manner shown and described in the copending applications of George Sauer, Serial Nos. 716,415 and 716,416, filed March 19, 1934.

The rotary hook is of the usual cup-shaped construction having a rim portion l I, a hub l6 and spaced radial spokes l8 connecting the hub and rim portion. The bobbin casing i9 is provided with a circumferential rib 20 which fits within a groove or raceway 2| in the rim portion ITI of the rotary hook. The rib 20 and raceway 2| form interengaging parts between the rotary hook and the stationary bobbin casing to prevent lateral movement of the casing relative to the rotary hook. The bobbin casing is also cupshaped to receive a bobbin 22 which is held by a cover or carrier 23. The bobbin casing is provided with a projecting portion 24 which engages a fixed part of the sewing machine and prevents The hub l6 of the rotary hook is secured onthe end of the shaft l3 in position to leave a recess 26 therein which is closed by a plate 2'! in order to provide a closed recess to prevent lubricant from passing directly to the inner face of the hook. The webs or connecting portions 28 between adjacent spokes l8 are provided with radial ports 29 which communicate with the recess 26 in the hub l6. As shown in Figs. 1-5, U-shaped channel forming members 30 having depending sides 30a are fitted over the connecting portions 28 between adjacent spokes to provide suitable lubricant conducting channels leading up the edges of adjacent spokes. The extreme edges of the spokes are inclined inwardly of the rotary hook, as at 3|, and merge into the inclined inner face 32 of the rim portion H.

The depending bearing bracket II is provided with an oil hole 33 which communicates with an opening 34 in the bushing l2. The shaft I3 is provided with an axial recess 35 which opens into the recess 26. A radial opening 36' in the shaft l3 permits oil to pass from the oil hole 33 through the opening 34 in the bushing to the axial recess 35 in the shaft from which it passes into the recess 26 in the hub [6 of the rotary hook. As the hook rotates, oil will be caused to flow by centrifugal force through the ports 29 to the channels formed by the channel members 30 along the connecting portions 28 between adjacent spokes [8. Oil will flow along the connecting portions to the inclined edges 3| of the spokes and from there the oil will be caused to" flow along the inner face 32 of the rim I! to the interengaging parts between the rotary hook and the stationary bobbin casing, that is, to the interfitting rib 20 and raceway 2|.

In Figs. 6-8 inclusive, a slightly modified form of the invention is shown. The manner in which the rotary hook, the bobbin 22 and bobbin casing 19 are assembled is the same as described in connection with Figs. 1-5. Similarly, the oil reaches the recess 25 in the hub 16 of the rotary hook from the recess 35 in the shaft l3 in the manner shown in Figs. 1-5, so that further description thereof at this time is not necessary. The webs or connecting portions 280:. between adjacent spokes I841, in this form of the invention, are provided with ports 29 which communicate with the recess 26 in the hub It. From the outer end of each port 29, a groove 36 extends along each connecting portion 281]. and spoke [8m in a direction opposite to the direction of rotation of the hook, as indicated by the arrows A in Fig.- 7.

The grooves 36 lead to an inclined edge .31 oneach spoke which merges into the inclined inner face 32 of the rim I1. Oil reaching the recess 26 from the oil hole 33 and recess 35 will be caused to flow by centrifugal force through the ports 29 to the grooves 36. As the rotary hook rotates in the direction indicated by the arrows, the oil will be caused to pass al the grooves 36 in the opposite direction and will be directed by the inclined edges 31 along the inner face 32 of the rim I! to the interengaging parts between the rotary hook and the stationary bobbin casing to lubricate the rib 23 and raceway 2!.

While a plurality of ports and oil channels along the spokes have been illustrated, it is to be understood that only one may be employed, if desired. The present invention provides a highly efiicient means for lubricating the interengaging parts between the rotary hook and the stationary bobbin casing, and it is to be clearly understood that minor changes in the details of construction and arrangement of parts may be I made without departing from the scopeof the.

invention as set forth in the appended claims.

Having thus described the invention, what I claim as new and desire to secure by Letters Patent, is: V

1. In a sewing machine, the combination of a rotary hook having a hub, a rim portion and connected spokes joining said hub and rim portion, a stationary bobbin casing supported within said rotary hook, said casing and said rim por-' tion having interengaging parts to prevent relative lateral movement between said hook and said casing, and means for furnishing lubricant from a supply at the axis of said hub to said interengaging parts and including lubricant conducting means on the edge of one of the connecting portions between adjacent spokes.

2. In a sewing machine, the combination of a rotary hook having a hub, a rim portion and connected spokes joining said hub and rim portion, a stationary bobbin casing supported withinsaid rotary hook, said casing and said rim portion having interengaging parts to prevent relative lateral movement between said hook and said casing, and means for furnishing lubricant from a supply at the axis of said hub to said interengaging parts and including lubricant conducting passages formed on the connecting portions between adjacent spokes.

3. In a sewing machine, the combination of a rotary hook having a hub, a rim portion and spokes connecting said hub and rim portion, said spokes being joined adjacent said hub by web portions,- of a stationary bobbin casing supported within said hook, said rim portion and casing having interengaging parts to prevent relative lateral movement between said hook and said casing, means for forming lubricant conducting passages along the edges of said web portions to the inner face of said rim portion, and means for furnishing lubricant from a supplyat the axis of said hook to said web portions whereby lubricant will be caused to flow to said interengaging parts.

4. In a sewing machine, the combination of a rotary hook having a hub, a rim portion and nishing lubricant from a supply at the axis of said hub to said interengaging parts and including a removable member secured to a web portion and forming therebetween a channel through which lubricant is caused to flow.

5. In a sewing machine, the combination of a rotary hook having a hub, a rim portion and spokes connecting said hub and rim portion, said spokes being joined adjacent said hubby web portions, of a stationary bobbin casing supported in said hook, said casing and said rim portion having interengaging parts to prevent relative lateral movement between said hook and said casing, said hub having a lubricant containing recess at the axis thereof, ports leading from said recess to said web portions and through which lubricant is caused to flow by centrifugal force, and means for directing lubricant to said interengaging parts and including grooves in said web portions extending from said ports in a direction opposite to the direction of rotation of said hook whereby lubricant is caused to flow to the inner face of said rim and to said interengaging parts.

6. In a sewing machine, the combination of a rotary hook having a hub, a rim portion and spokes connecting said hub and rim portion, said spokes being joined adjacent said hub by web portions, of a stationary bobbin casing supported within said hook, said casing and rim por-- tion having interengaging parts to prevent relative lateral movement between said hook and said casing, an actuating shaft on which said hub is secured in position to leave a lubricant containing recess, means for furnishing lubricant to said recess, ports passing radially through said web portions and communicating with said recess, whereby lubricant is caused to flow therethrough by centrifugal force, and a channel member tightly fitting over the edge of each of said web portions and extending along the edges of adjacent spokes and forming therebetween lubricant conducting passages, said spokes having inclined edges merging into the inner face of said rim portion whereby lubricant is caused to flow through said passages to said interengaging parts by centrifugal force.

7. In a sewing machine, the combination of a rotary hook having a hub, a rim portion and spokes connecting said hub and rim portion, said; spokes being joined adjacent said hub by web portions, of a stationary bobbin casing supported within said hook, said casing and rim portion having interengaging parts to prevent relative lateral movement between said hook and said casing, an actuating shaft on which said hub is secured in position to leave a lubricant containing recess, means for furnishing lubricant to said recess, ports passing radially through said web portions and communicating with said recess, whereby lubricant is caused to flow therethrough by centrifugal force, and a groove formed in the edge of each of said web portions and extending from the adjacent port along the edge of one spoke in a direction opposite to the direction of rotation of said hook, each of said spokes having an inclined edge at the end of said groove merging into the inner face of said rim portion whereby lubricant is caused to flow by centrifugal force along said grooves to said interengaging parts.

HAROLD J. LE VESCONTE. 

